Pollution pad reconditioning/recycling system

ABSTRACT

A pollution pad cleaning system for recyclably removing hydrocarbons from an absorbent material such that the material is re-useable as originally designed. As the preferred embodiment a pollution pad cleaning system comprises a multi-stage treatment process wherein polypropylene absorbent pads soaked with waste oil and the like are treated via a system of squeeze rollers, a solvent shower, centrifuge spin, and then drying and fluffing, restoring the pads to a &#34;like new,&#34; reusable condition. The collected waste oil and solvent are removed at a predesignated concentration from the system for recycling. While the preferred embodiment utilizes a continuous system with conveyors and the like, and wherein the contaminated pads are placed upon the ingress portion of the system and the cleaned, reusable pads are discharged from the exit end of the system, an alternative, working embodiment utilizes a system comprising a plurality of treatment stations which may be economically configured utilizing a minimum of labor and start-up costs. The present invention provides an inexpensive, environmentally sound method of treating and recycling pollution absorbing pads wherein in the past the pads were disposed of in landfills, creating still another pollution problem, and at a disposal cost greater than the cost of implementing the present cleaning and recycling system.

This application is a continuation of application Ser. No. 07/749,892,filed Aug. 26, 1991 now U.S. Pat. No. 5,192,455.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to systems f or cleaning and recyclingmaterials for absorbing hydrocarbons and the like, and in particular toa pollution pad cleaning system for recyclably removing hydrocarbonsfrom an absorbent material such that the material is re-useable asoriginally designed.

The preferred embodiment of the present invention teaches a pollutionpad cleaning system comprising a multi-stage treatment process, whereinpolypropylene absorbent pads soaked with waste oil and the like aretreated via a system of squeeze rollers, a solvent shower, centrifugespin, and then drying and fluffing, restoring the pads to a like new,reusable condition. The collected waste oil and solvent are removed at apredesignated concentration from is the system for recycling.

While the preferred embodiment of the present invention teaches acontinuous system via the utilization of conveyors and the like, andwherein the contaminated pads are placed upon the ingress portion of thesystem and cleaned, reusable pads are discharged from the exit end ofthe system, an alternative, working embodiment of the present inventionteaches a system comprising a plurality of treatment stations which maybe economically configured utilizing a minimum of labor and start-upcosts.

The present invention provides an inexpensive, environmentally soundmethod of treating and recycling pollution absorbing pads. This is incontrast to the past practice when such pads were disposed of inlandfills, creating still another pollution problem, and at a disposalcost greater than the cost of implementing the present cleaning andrecycling system of the invention.

2. Prior Art & General Background

While the prior art is replete with various designs for oil absorbentmaterials and the like, none teach or contemplate a system for recyclingthe materials in a manner contemplated by their use, while recycling theabsorbed liquid.

A list of prior patents which may be of interest is presented below:

    ______________________________________                                        Patent No.  Pantentee(s) Issue Date                                           ______________________________________                                        4,981,097   Beyrouty     01/01/1991                                           4,969,774   Arseneeault et al.                                                                         11/13/1990                                           4,965,129   Bair et al   10/23/1990                                           4,925,343   Raible et al 05/15/1990                                           4,919,820   Lafay et al  04/24/1990                                           4,737,394   Zafiroglu    03/12/1988                                           4,652,372   Threadgill   03/24/1987                                           4,497,712   Cowling      02/05/1985                                           4,401,471   Eckardt et al                                                                              08/30/1983                                           4,371,441   Mathes et al 02/01/1983                                           4,341,637   Smith        07/27/1982                                           ______________________________________                                    

A review of the prior art reveals that there have been taught in thepast various methods of absorbing oil utilizing a variety of materialsand systems. However, it will be shown below that none contemplate asystem f or removing the absorbed hydrocarbons in such a manner as toallow them to be recycled, while allowing the absorbent material to bereutilized in the manner which it was originally intended.

For example, U.S. Pat. No. 4,969,774 issued 1990 teaches the utilizationof "precooked and puffed cereals as oil spill sorbents", but does notteach or suggest a system wherein the absorbent materials can berecycled. Interestingly, the disclosure recognizes that absorbent padscan pose environmental hazards once used.

U.S. Pat. No. 4,925,343 issued 1990 teaches a composition containingwood fiber for absorbing oil, but teaches as the only disposal remedyfor the hydrocarbon-soaked composition burial or burning.

U.S. Pat. No. 4,919,820 issued 1990 teaches the utilization of meshcontainers containing waterfowl feathers for absorbing oil and the like,recognizing that "Reclamation of the oil may be effected by squeezingthe container and feathers therein to separate the oil from thefeathers, and collecting the separated oil . . . " it is submitted,however, that once the waterfowl feathers become saturated with oil,their absorption capability will be greatly decreased, and squeezing theoil will not sufficiently remove the contaminants to allow forperformance near approaching the first usage.

U.S. Pat. No. 4,737,394 issued 1988 teaches an oil-absorbing articlecomprising a porous outer fabric of polyethylene or polypropylene whichencloses fibrous oil absorbing particles. While the specification doesnot teach the recycling of the article, there is disclosed the handwringing of the absorbed liquid from the article, and an indication that"the samples readily absorbed about an equal quantity of oil as waswrung out, even after the procedure was repeated several times . . . "(Col 7 Lines 3-6.)

U.S. Pat. No. 4,652,372 issued 1987 teaches an endless-belt type skimmercomprising an oleophilic belt and squeeze system for removing thehydrocarbons, and there are a number of these types of skimmers known inthe art.

U.S. Pat. No. 4,497,712 issued 1985 teaches an absorbent pillowutilizing corn cob material for absorbing hydrocarbons, wherein the usedpillow "may be utilized by a utility company or other type of company asfuel in a furnace . . . Alternatively, the pillow bay be used as landfill . . . "

U.S. Pat. No. 4,341,637 issued 1982 teaches an endless belt type skimmerwherein the oil is removed via pressurized steam applied to the belt.

As may be discerned from a review of the above, the prior art has failedto teach or contemplate a system for the economical and environmentallysound recycling of absorbent materials for absorbing liquid hydrocarbonsand the like, and has at best suggested less destructive ways ofdisposing the used materials.

The '820 reference was the only patent to suggest any procedure forproviding limited re-use of the absorbent, with that procedure limitedonly to the wringing out of the liquid. However, it is submitted thatany re-use would appear to be limited, and without the results achievedin its first use. The '394 reference also discussed some hand wringingof the composition it claimed, but again it is submitted that wringingof the composition it claimed, but again it is submitted that wringingis insufficient to provide a re-useable system, as residue remains whichis dirty, collects other contaminants, and may pose health and furtherenvironmental hazards during use. Further, it is averred that theabsorption characteristics must and will be less with an uncleanabsorption material, effecting its performance.

GENERAL SUMMARY DISCUSSION OF THE INVENTION

The present invention, effective system for relatively inexpensive, safeand highly sorption pads and removing liquid hydrocarbons and the likefrom absorption pads and other compositions, allowing their repeatedre-use, as well as reclamation and recycling of the absorbed liquid.

The preferred, exemplary embodiment of the present invention teaches aconveyor-type arrangement wherein the used absorption pads are drained,squeeze rolled, exposed to a solvent shower, rerolled, spun in acentrifuge, air dried, fluffed and repackaged.

This conveyor driven system allows for the processing of the pads suchthat they are cleaned and ready for re-use with nominal labor and at alesser time rate than the alternative system discussed below.

The alternative embodiment of the present invention teaches a systemwherein each step is performed in separate stations, with the workpieces moved by hand f rom one step to the next. While this system maybe slightly more expensive to operate, it offers the advantage of lesserstart-up costs.

The system teaches the utilization of a recirculating solvent shower forcleaning the pads of residual oil and the like and removing the oil foreventual recycling.

The present system not only provides a cost savings relative to thepurchase of new pads, but is in fact substantially less costly than thedisposal of the used pads, which disposal, which nay includeincineration or disposal in a hazardous waste facility, can easily runover, for example, two hundred ($200.00) dollars per fifty-five (55)gallon drum of pads.

It is another object of the present invention to provide an effective,safe, yet inexpensive system for recycling and reconditioninghydrocarbon liquid absorption pads, wherein the absorbed hydrocarbonliquid is collected and is suitable for recycling.

It is another object of the present invention to provide a system forrecycling pollution pads and the like wherein the pads are restored to aclean, residue free condition suitable for re-use as originally designedand contemplated, with similar effectiveness.

It is still another object of the present invention to provide a systemfor the reconditioning and recycling of the pollution pads and the like,wherein there is provided a recirculating solvent shower for removingresidue from the used pads.

Lastly, it is an object of the present invention to provide a system forthe reconditioning and recycling of pollution pads and the like whichmay be utilized with a variety of, hydrocarbon liquids and diverse otherfluids.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature and objects of the presentinvention, reference should be had to the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like parts are given like reference numerals, and wherein:

FIG. 1 is a view of a f low chart setting forth the pollution padreconditioning/recycling system of the preferred embodiment of the ofthe present invention.

FIG. 2 is a generalized, simplified view of a first, exemplary,preferred embodiment of the present invention utilizing the steps andstages of the f low chart of FIG. 1 in an integrated, more automatedsystem.

DETAILED DESCRIPTION OF THE PREFERRED, EXEMPLARY EMBODIMENTS

As can be seen in FIGS. 1 and 2, the pollution pad recycling process ofthe preferred, exemplary embodiment of the present invention, includes amultiple-step system, wherein there is provided means for cleaningcontaminated pollution pads, which typically are contaminated withliquid hydrocarbons such as oil (crude or refined) and derivativesthereof.

In the present process, multiple individual pads P, typically measuringseventeen inches by nineteen inches (17"×19"), are placed by the userin, for example, a fifty-five (55) gallon drum and forwarded to theexemplary facility of the present invention. This is in contrast to theprior art wherein the pads were disposed of at substantial loss, botheconomically and environmentally, in a waste facility.

The drums are received (step 1), the contaminated pads are removed andshaken to remove any soil or solid contaminants therefrom, and thenplaced in a drain container 11 having an approximate capacity of, forexample, two hundred (200) gallons, with screens 12 and a drain 13 atthe base 14 for allowing the draining of any excess fluid contaminantsfrom the pollution pads.

In the preferred embodiment of the present invention, typically thesystem is processed utilizing, for example, seventy (70) pound batchloads for each step. However, this figure can vary widely depending uponthe volume, contamination of the product, and state and capacity of thevarious components of the present system.

After draining, typically for, for example, about ten to twenty (10-20)minutes, each pad is individually passed through a power roller 3, 15for the further squeezing out of the liquid contaminants. The exemplaryembodiment of the present invention utilizes a conventional heavy duty,powered roller operating at a speed of, for example, approximately sixty(60) revolutions per minute, with preferably foot control means 16 forinitiating power on or off.

After having passed through the roller, the batch is ready for cleaningand is then placed in a single layer upon a drain screen 17 under atleast one shower head 18 configured to provide a recirculating solventshower 4, 19 for further removing the is hydrocarbon contaminants andother residues on the pads. The exemplary, preferred solvent utilized inthe present system is varsol, which is found to work well with mostpollution pads, which typically are fabricated from polypropylene.

It is noted that it has been found that the shower preferably should notincorporate degreasers or detergents, as their presence would cause thepolypropylene pads to absorb water in any future use of the cleaned pad.The ability to absorb water is an undesirable characteristic for apollution pad, which is designed to absorb hydrocarbon and relatedcontaminants but allow water to remain unabsorbed.

In operation, the shower disperses the solvent evenly over the pads,which drains therethrough, dissolving the hydrocarbons and contaminantsfrom the pads , allowing them to drain out of the pads, through thedrain screen 19, and into the drain tank 20. There the varsol can berecirculated for showering more pads until the hydrocarbon/contaminantconcentration 21 therein has arise to too high amount to allow theoverly contaminated varsol to serve as an effective cleaner, which hasbeen found to be on the order of, for example, thirty (30%) percenthydrocarbon/contaminant.

The varsol shower's drain screen has dimensions of, for example, fourfeet by eight feet (4'×8') feet, with multiply dispersed, gentle spraynozzles configured for uniform soaking of the pads. The presentexemplary embodiment has, for example, fifteen (15) spray nozzles in theform of, for example, converted natural gas burners. Further, thepresent system utilizes, for example, a five hundred (500) gallonsolvent tank, with a three (3) horsepower electric impeller type pumpfor circulating the solvent.

While the time in the shower varies depending upon the degree and typeof contamination, the material of the pads, and the type of solvent, theexemplary embodiment of the present invention typically utilizes theshower step for, for example, ten to fifteen (10-15) minutes before thepads have been sufficiently cleansed to allow for the progression to thenext step, which achieves on the order of ninety-seven to ninety-nine(97-99%) percent hydrocarbon and contamination removal.

It is noted that once the solvent has been contaminated so as to make itunusable any longer in the present process, it may be sold to an oilrecycler for re-refining into useable hydrocarbon products.

After the pads have been allowed to drain on the drain screen of theshower (note 4) after the varsol spray has ceased, each pad is then onceagain placed through a roller 5, 15 of the type utilized in step 3above. It is estimated that this step removes, for example,approximately eighty-five (85%) of the residual varsol or other solventfrom the pollution pad.

Once the pads have been squeezed, the batch is then placed in a largecentrifuge extractor 22 (note 6), wherein the batch is rotated at a rateof I f or example, seven hundred and fifty to a thousand (750-1000)revolutions per minute. Again, while the time varies depending upon thetype and weave of material in the pads and the degree of residualsolvent, the exemplary embodiment of the present invention typicallyspins the batch load for, for example, ten (10) minutes in thecentrifuge, typically removing another, for example, twelve to thirteen(12-13%) percent of the residual varsol or other solvent.

After the batch load has been extracted in the centrifuge 6, the load isthen placed in a commercial type air tumbler/dryer 7, 23 forapproximately twenty to thirty or more (20-30+) minutes for removal ofthe remaining, for example, three to four (3-4%) percent varsol or othersolvent. Depending upon the humidity, temperature, material of the padand the type of solvent, the air dryer may have heated air at variousappropriate temperatures, or it may be at room temperature.

Following the drying process, the batch load of cleaned pads is thenplaced upon a table or the like and fluffed 8, either by hand ormachine, in order to provide a pollution pad of similar appearance,consistency, and performance as it may have had prior to itsutilization.

Once fluffed, the pads are then ready for bagging, rebagging 9 or likepackaging, which may include placement of multiples of the pads inplastic bags or the like and re-placement into the drum(s) the padsarrived in, after the drum itself has been cleaned of contaminants.

Once packaged, the batch load is ready for delivery and reuse, endingthe recycling process 10, until the load is contaminated again and readyfor re-processing.

It is estimated that a batch load comprised of general purpose"disposable" polypropylene pads will, with the present system, can beprocessed at least, for example, about five to seven (5-7) times,thereby avoiding the disposal and replacement costs of, for example,$1,372.00 dollars per pad with one batch.

It is noted that, while the exemplary embodiment of the presentinvention of FIG. 2 illustrates a system wherein the steps can bepracticed sequentially with hand labor interceding to move the batchesfrom one step or stage to another, the present system is preferablyimplemented in conjunction with a conveyor system C to allow for acontinuous process, substantially increasing the volume processingcapability of the present system and decreasing processing costs due tolabor.

Further, the present system is not limited solely to pollution padswhich have hydrocarbon contamination therein, but may be utilized withregard to any contaminant, as long as there can be provided a solventfor removing that contaminant in the shower step 4.

The embodiments described herein in detail for exemplary purposes are ofcourse subject to many different variations in structure, design,application and methodology. Because many varying and differentembodiments may be made within the scope of the inventive concept(s)herein taught, and because many modifications may be made in theembodiments herein detailed in accordance with the descriptiverequirements of the law, it is to be understood that the details hereinare to be interpreted as illustrative and not in a limiting sense.

What is claimed is:
 1. A method of removing liquid hydrocarbons frompollution pads, restoring the pollution pads to a reusable state,comprising the following steps:A. providing an apparatus for the removalof liquid hydrocarbons from pollution pads comprisingdrain means fordraining excess liquids from the pollution pads; squeeze meansassociated with said drain means for squeezing out additional liquidfrom pollution pads; a recirculating liquid cleaning area having anupper portion and a medial portion for diluting and removing the liquidhydrocarbons from the pollution pads, said recirculating liquid cleaningarea further includingat least one liquid cleaning area forming theupper portion of said recirculating liquid cleaning area, said liquidcleaning area being configured for evenly dispersing a fluid solventover the liquid cleaning area; fluid permeable means for positioningpollution pads within the liquid cleaning area, said fluid permeablemeans forming the medial area of said recirculating liquid cleaningarea; basin means for receiving a quantity of cleaning fluid, comprisingthe solvent and a percentage of the liquid hydrocarbon permeating saidfluid permeable means, said basin means further including storage meansfor storing said fluid; and circulation means for circulating thecleaning fluid from said basin means to said liquid cleaning area, saidcirculation means further comprising a fluid pump and fluid conveyingmeans directed from said basin to said liquid cleaning area; saidapparatus further comprisinga centrifuge extractor for extracting fluidabsorbed by the pollution pads after having been treated by saidcleaning fluid; and a tumble dryer for drying residual solvent absorbedby the pollution pads; B. draining said pollution pads in said drainmeans for a period of time so as to allow draining of any excess fluidsfrom the pollution pads; C. squeezing the pollution pads through saidsqueeze means so as to remove additional fluid from the pollution pads;D. positioning the pollution pads in association with said fluidpermeable means; E. cleaning the pollution pads with a solvent, therebydiluting and substantially removing any remaining absorbed liquidhydrocarbons; F. draining the solvent from the cleaned pollution pads;G. squeezing the pollution pads again through said squeeze means; H.extracting the remaining absorbed solvent from the pollution pads byplacing them in a centrifuge and spinning them in a centrifuge andspinning them; and I. tumbling the pollution pads in a tumble dryeruntil any remaining solvent in the pollution pads has drained orevaporated.
 2. The method of claim 1, wherein after step "I" there isfurther included the step of fluffing the pollution pads.
 3. The methodof claim 1, wherein after step "I" there is further included the step ofbagging the pollution pads.
 4. The method of claim 1, wherein saidcleaning area includes a shower connected to said fluid cleaning meansfrom said basin, and in step "E" there is further included the step ofbathing the pads by showering the cleaning fluid solvent unto thepollution pads, evenly dispersing the cleaning fluid unto the pads. 5.The method of claim 1, wherein in step "H" there is further included thestep of spinning the pads at a rate of about seven hundred to a thousand(700-1000) revolutions per minute.